West Gabbard zooplankton abundance time series monitoring using ZooScan from 2016 to 2022

Estimates of zooplankton taxa abundances identified and analysed using semi-automated methods with the ZooScan instrument and EcoTaxa web application. Data are obtained from opportunistic ringnet sampling at the West Gabbard sampling location as part of a time series. The dataset currently contains the results from zooplankton samples obtained from 30/06/2016 - 17/12/2020, although the time series is ongoing. After subsequent image analysis, the sampling information and results are analysed to provide abundance estimates for zooplankton taxa in m3. Since 30th June 2016, opportunistic sampling has been undertaken by the RV Cefas Endeavour throughout the year by vertically deploying 0.5m 200µm mesh ringnets at the West Gabbard sampling location. Samples are sent back to the Plankton Lab at the Lowestoft laboratory. These are then prepped and scanned for image analysis using ZooScan, with the obtained images subsequently being imported into the EcoTaxa project library. Once uploaded into EcoTaxa, sample scan images are predicted into taxa categories with the provision of a learning set to aid automatic image sorting using Random Forest algorithms. These predicted classifications are validated afterward by an experienced taxonomist and the metadata downloaded. Objects captured in images are separated into zooplankton taxa and detritus groups and abundances are estimated (per meter cubed) using counts and sample fraction calculations. An agreed subset of the data may be selected for QC checks by a second analyst.